1. Field of the Invention
The present invention relates in general to electrically powered door actuating systems, and more particularly to the systems of a type that employs an electric motor or the like for moving a vehicle door in opening/closing direction.
2. Description of the Related Art
Hitherto, various types of electrically powered door actuating systems have been proposed and put into practical use particularly in the field of motor vehicles. For protecting passengers from the moving door, almost all of the door actuating systems hitherto proposed employ a safety system that includes an obstacle sensor or sensors. That is, when, under opening/closing movement of the door, the sensor detects an obstacle ahead on a track of the door, the safety system stops the movement of the door or reverses the direction in which the door is moving. As the obstacle sensor, contact type and non-contact type have been used, which are shown in for example Japanese Laid-open Patent Application (tokkai) 2007-308929 and Japanese Laid-open Patent Application (tokkai) 2007-138566 respectively.
In the contact type, existence of an obstacle is detected by a direct contact of the sensor with the obstacle, while in the non-contact type, the existence of the obstacle is detected without contacting the obstacle.